Astrophile: A scorched world with snow black and smoky

Astrophile is our weekly column on curious cosmic objects, from the solar system to the far reaches of the multiverse

Object: Titanium oxide snow
Location: The hot-Jupiter planet HD 209458b

There is something magical about waking up to discover it has snowed during the night. But there's no powdery white blanket when it snows on exoplanet HD 209458b. Snow there is black, smoky and hot as hell – resembling a forest fire more than a winter wonderland. Put it this way: you won't be needing mittens.

HD 209458b belongs to a family called hot Jupiters, gas-giant planets that are constantly being roasted due to their closeness to their sun. By contrast, the gas giants in our immediate neighbourhood, including Jupiter, are frigid, lying at the solar system's far reaches.

HD 209458b is also noteworthy because it is tidally locked, so one side is permanently facing towards its star while the other is in perpetual night. On the face of it, these conditions wouldn't seem to invite snow: temperatures on the day side come close to 2000° C, while the night side is comparatively chilly at around 500° C.

Snow made of water is, of course, impossible on this scorched world, but the drastic temperature differential sets up atmospheric currents that swirl material from the day side to night and vice versa. That means that any substances with the right combination of properties might be gaseous on the day side and then condense into a solid on the night side, and fall as precipitation. Say hello to titanium oxide snow.

Stuck on the surface

Although oxides of titanium make up only a small component of a hot Jupiter's atmosphere, these compounds have the right properties to fall as snow. But there was a snag that could have put a stop to any blizzards. Older computer models of hot Jupiters suggested that titanium oxides condensing in the air on the night side would snow – and remain on the relatively cool surface forever. "Imagine on Earth if you had no mechanism to evaporate water, it would never rain," says Vivien Parmentier of the Côte d'Azur Observatory in Nice, France.

Now he and colleagues have created a more detailed 3D computer model that shows that the snow can become a gas again as it falls and the temperature and pressure increase. Strong updraughts can then blow the titanium oxides back to the upper atmosphere. "The gas can come back on the top layers and snow again and again," says Parmentier.

Snowfall on HD 209458b would be like none you've ever seen. Though titanium dioxide is white and shiny, for example, the snowflakes would also contain silica oxides from the atmosphere, making them black. Since the atmosphere is also dark, snowstorms on the planet would be a smoky affair, the opposite of the white-outs we get on Earth. "It would be like being in the middle of a forest fire," says Parmentier.

Although the team studied a particular hot Jupiter, their model should apply equally to other planets of this type, suggesting hot snow is a common occurrence. Parmentier says we may have already spotted snow clouds on another hot Jupiter, HD 189733b, as spectral analysis of the planet suggests the presence of microscopic particles in its atmosphere.

David Sing of the University of Exeter, UK, who helped identify such particles on HD 189733b, says the team's new model goes a long way to explaining how titanium oxides behave on hot Jupiters. "We're pretty used to water condensing on Earth; there it is titanium because the temperatures are so much hotter."

Hot, black snow – now that would be something to wake up to.

Reference: http://arxiv.org/abs/1301.4522

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India set to introduce death penalty in some rape cases

NEW DELHI - India's Cabinet has approved harsher punishments for rapists, including the death penalty, after a brutal gang-rape in New Delhi that sparked national outrage.

A government-appointed panel recommended the changes to ministers after the death of a 23-year-old woman who was savagely raped and attacked in a bus on December 16 and died nearly two weeks later.

The case ignited nationwide demonstrations by protesters demanding better safety for women.

The changes, which must be approved by President Pranab Mukherjee to become law, include doubling the minimum sentence for gang-rape and imposing the death penalty when the victim is killed or left in a vegetative state.

"We have taken swift action and hope these steps will make women feel safer in the country," Law Minister Ashwani Kumar told reporters late on Friday.

"This is a progressive piece of legislation and is consistent with the felt sensitivities of the nation in the aftermath of the outrageous gang-rape," he added.

On Saturday, the gang-rape victim's brother praised the Cabinet's decision to make sentences tougher for attackers, calling it a "positive initiative", according to the Press Trust of India news agency.

The changes to the rape laws were expected to be approved by Mukherjee as early as this weekend but must be ratified by parliament or they will lapse.

Under the changes, the minimum sentence for gang-rape, rape of a minor, rape by policemen or a person in authority will be doubled to 20 years from 10 and can be extended to life without parole.

Under the current law, a rapist faces a term of seven to 10 years.

The Cabinet has also created a new set of offences such as voyeurism and stalking that will be included in the new law.

Five men are being tried in a special fast-track court in New Delhi on charges of murder, kidnapping and rape in connection with the death of the student, who died from her injuries.

A sixth suspect faces trial in a juvenile court.

The physiotherapy student was assaulted on a bus she had boarded with a male companion as they returned home from watching a film in an upmarket shopping mall.

India says it only imposes the death penalty in the "rarest of rare cases". Three months ago, it hanged the lone surviving gunman from the 2008 Mumbai terror attacks -- the country's first execution in eight years.

Verdicts for the five men would be handed down "very soon", a defence lawyer said earlier in the week, as an application to relocate the trial outside of the capital failed.

A separate court has ruled that a sixth suspect in the case should be tried as a juvenile after it accepted his claim based on his school certificate that he was aged 17.

The decision, which means he faces a maximum of three years if convicted instead of the death penalty, has appalled the victim's family who said they would call for an exception to be made in the case.

Indian media reports, citing unnamed police officials, say the 17-year-old was among the most brutal of the assailants, who are accused of attacking the woman with an iron bar, causing horrifying internal injuries.

- AFP/ir

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Clinton's final day in job marred by bombing

STORY HIGHLIGHTS

• NEW: Kerry sworn in, first trip likely to include stops in Egypt and Israel


• Clinton cites Turkey attack as example of challenges in the world


• Clinton visited 112 countries and flew almost 1 million miles in four years


• At 65, Clinton faces questions about whether she'll run for president in 2016

Washington (CNN) -- A final meeting with the president. A farewell address to the State Department staff. A terrorist attack at the U.S. Embassy in Turkey.

Hillary Clinton's last day as secretary of state on Friday seemed to be a microcosm of her four globe-trotting years as America's top diplomat.

The former first lady had a full schedule, as usual, meeting in private with President Barack Obama at the White House and then attending the send-off ceremony with clapping, cheering workers at the agency she led.

Those events were clouded by a suicide bombing earlier in the day in Ankara that killed the attacker and a Turkish security guard at the embassy. No Americans were killed or injured.

Hillary Clinton through the years

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Clinton traveled nearly 1 million miles and visited 112 countries in her quest as secretary to promote better understanding of the United States and its role in the world.

On the road with Hillary Clinton

However, her tenure will also be remembered for last September's attack on a diplomatic compound in Benghazi, Libya, that killed Ambassador Christopher Stevens and three other Americans.

Amid the good wishes and emotions of Clinton's farewell, Friday's bombing in Turkey was a grim reminder of the continuing threats and challenges to U.S. diplomatic efforts.

"Of course we live in very complex and dangerous times as we saw again just today at our embassy in Ankara," Clinton told the State Department ceremony.

"I know the world we are trying to help bring into being in the 21st century will have many difficult days," she added. "But I am more optimistic today than I was when I stood here four years ago."

Standing in front of a sign that said "Thank You," Clinton told the staffers jamming the area that she would miss them and the important work they do around the world.

"I will probably be dialing ops just to talk," she said to laughter.

Clinton sent her resignation letter to Obama a few hours before her successor, John Kerry, was sworn in on Friday afternoon.

Opinion: Clinton, secretary of empowerment

"It has been an honor to serve in your administration and to represent our country around the world," the letter said.

"I am proud of what we have accomplished together on behalf of the American people and in pursuit of our interests and values. And I am more convinced than ever in the strength and staying power of America's global leadership and our capacity to be a force for good around the world," she said.

In what was billed as Clinton's farewell speech on Thursday at the Council on Foreign Relations, she said the United States needs to build "smart power" in a world where the levers of influence are changing rapidly.

American diplomats have to work with entrepreneurs and activists, use new technological tools such as social media and update the global and regional institutions that have dominated international affairs since World War II, Clinton said.

"We need a new architecture for a new world -- more Frank Gehry than formal Greek," she said. "Now some of his work at first might appear haphazard, but in fact, it's highly intentional and sophisticated. Where once a few strong columns could hold up the weight of the world, today we need a dynamic mix of materials and structures."

Clinton defends her diplomatic legacy

Clinton called the United States "uniquely well-positioned" to help construct that metaphorical global edifice.

"Those things that make us who we are as a nation --- our openness and innovation, our diversity, our devotion to human rights and democracy --- are beautifully matched to the demands of this era and this interdependent world," she said.

Kerry, who served nearly 30 years in the Senate, stepped down Friday ahead of his swearing-in as the nation's 68th secretary of state.

He was chairman of the Senate Foreign Relations Committee and the Democratic nominee for president in 2004, when he lost to incumbent President George W. Bush.

Kerry expects to take his first official overseas trip in coming weeks, according to a U.S. official who said stops would likely include Israel and Egypt.

Exiting State, Clinton looks to writing, speaking

Clinton, 65, now faces persistent questions about whether she will mount a second White House run in 2016 to break perhaps the highest remaining glass ceiling.

"Well I'm not thinking about anything like that right now. I'm looking forward to finishing my tenure as secretary of state and catching up on 20 years of sleep deprivation," Clinton said Tuesday at a global "town hall" forum in Washington.

Observers note her answer was a less emphatic denial than previous responses that seemed to rule out any possibility of reentering the political fray.

According to a CNN/ORC International poll conducted last month, 85% of Democrats and independents who lean toward the Democratic Party said they would be very or somewhat likely to support Clinton if she sought the Democratic nomination.

Clinton was considered a favorite in 2008, but Obama, who served with her in the Senate, got an early jump in the primaries. Clinton was unable to capture the momentum in a fierce political battle.

Despite the rugged campaign, Obama chose Clinton for his Cabinet and she embraced the role.

In a joint interview with CBS that aired on Sunday, Obama said that he believes Clinton's legacy will rank among the best.

"It has been a great collaboration over the last four years," Obama said. "I'm going to miss her."

Clinton touts 'smart power' in farewell talk

CNN's Elise Labott, Jill Dougherty and Matt Smith contributed to this report.

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Twitter: 250,000 users' data compromised in hacking attacks

#1157946: Twitter bird logo, social networking and microblogging service, graphic element on white / AP Graphics

Twitter said today that it recently detected a series of attempts to hack into user data, and that the attackers may have successfully absconded with some users' information.

In a blog post Friday afternoon, Twitter explained the situation, and the steps it has taken to fight off the hackers.

This week, we detected unusual access patterns that led to us identifying unauthorized access attempts to Twitter user data. We discovered one live attack and were able to shut it down in process moments later. However, our investigation has thus far indicated that the attackers may have had access to limited user information - usernames, email addresses, session tokens and encrypted/salted versions of passwords - for approximately 250,000 users. As a precautionary security measure, we have reset passwords and revoked session tokens for these accounts. If your account was one of them, you will have recently received (or will shortly) an email from us at the address associated with your Twitter account notifying you that you will need to create a new password. Your old password will not work when you try to log in to Twitter.

Twitter said in the post that a very small number of users were affected by the hacking, but it encouraged everyone who uses the service to ensure that they are practicing "good password hygiene, on Twitter and elsewhere on the Internet." Among its suggestions: using unique passwords of at least ten characters, including a mix of upper and lower case letters, numbers, and symbols. Based on attacks on other high-profile tech and media companies, Twitter also said it is recommending the U.S. Department of Homeland Security's recent advisory on disabling Java, among other precautions.

This attack was not the work of amateurs, and we do not believe it was an isolated incident. The attackers were extremely sophisticated, and we believe other companies and organizations have also been recently similarly attacked. For that reason we felt that it was important to publicize this attack while we still gather information, and we are helping government and federal law enforcement in their effort to find and prosecute these attackers to make the Internet safer for all users.

This article originally appeared on CNET under the headline "Twitter says 250,000 users' data compromised in hacking attacks"

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Gov's Handling of Sandusky Case Under Investigation

The newly-elected attorney general of Pennsylvania is going after the state's governor, Tom Corbett, who was attorney general when child sex allegations against Penn State coach Jerry Sandusky were first brought forward.

Kathleen Kane, a Democrat who was sworn in as attorney general on Jan. 15, said that she will name a special prosecutor in the coming days to investigate Corbett's handling of the Sandusky case. Corbett is a Republican.

The investigation will look specifically at why it took the attorney general's office three years to bring criminal charges against Sandusky while he continued to have access to children.

"Attorney General Kane will appoint a special prosecutor to lead the office's internal investigation into how the Sandusky child abuse investigation was handled by the Office of the Attorney General," Kane's office said in a statement released today.

Corbett's attorney general's office was first notified of the allegations against Sandusky in 2008 when a high school student told his mother and school that Sandusky had molested him. The local district attorney passed the allegation on to the attorney general, then Corbett. Corbett convened a grand jury.

Mario Tama; Patrick Smith/Getty Images

Jerry Sandusky Insists Innocence Before Sentencing Watch Video

Jerry Sandusky Sentencing: Why Did He Release Statement? Watch Video

Jerry Sandusky Claims Innocence in Audio Statement Watch Video

It wasn't until 2011 that sex abuse charges were filed against Sandusky while Corbett had since become governor. Sandusky was convicted on 45 counts of sex abuse in June 2012.

The charges sent shockwaves throughout Pennsylvania, as Penn State's president, two top officials, and legendary coach Joe Paterno all lost their jobs over the scandal.

"Why did it take 33 months to get Sandusky off the streets? Was the use of a grand jury the right decision? Why were there so few resources dedicated to the investigation? Were the best practices implemented?" the statement from Kane's office read.

"At the end of this investigation, we will know the answers to these questions and be able to tell the people of Pennsylvania the facts and give them answers that they deserve," the statement said.

Describing an interview Kane gave the New York Times, the Times said Kane suggested that Corbett did not want to upset voters or donors in the Penn State community before his gubernatorial run in 2009.

Corbett has denied those suggestions. His office did not immediately return calls for comment.

Kane's office preemptively fought back against the idea that the investigation is politically motivated. Kane, a Democrat, defeated the incumbent attorney general, Linda Kelly, a Republican in November 2011. Corbett is a Republican.

"The speculation that this is about politics is insane," a staff member in Kane's office told ABC News today. "You go anywhere in Pennsylvania and anywhere across the country and you'll find individuals asking, 'why did it take three years? Why was there a grand jury? Why make these kids talk to 30 different people about what happened?"

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Mind-meld brain power is best for steering spaceships

TURNS out two heads really are better than one. Two people have successfully steered a virtual spacecraft by combining the power of their thoughts - and their efforts were far more accurate than one person acting alone. One day groups of people hooked up to brain-computer interfaces (BCIs) might work together to control complex robotic and telepresence systems, maybe even in space.

A BCI system records the brain's electrical activity using EEG signals, which are detected with electrodes attached to the scalp. Machine-learning software learns to recognise the patterns generated by each user as they think of a certain concept, such as "left" or "right". BCIs have helped people with disabilities to steer a wheelchair, for example.

Researchers are discovering, however, that they get better results in some tasks by combining the signals from multiple BCI users. Until now, this "collaborative BCI" technique has been used in simple pattern-recognition tasks, but a team at the University of Essex in the UK wanted to test it more rigorously.

So they developed a simulator in which pairs of BCI users had to steer a craft towards the dead centre of a planet by thinking about one of eight directions that they could fly in, like using compass points. Brain signals representing the users' chosen direction, as interpreted by the machine-learning system, were merged in real time and the spacecraft followed that path.

The results, to be presented at an Intelligent User Interfaces conference in California in March, strongly favoured two-brain navigation. Simulation flights were 67 per cent accurate for a single user, but 90 per cent on target for two users. And when coping with sudden changes in the simulated planet's position, reaction times were halved, too. Combining signals eradicates the random noise that dogs EEG signals. "When you average signals from two people's brains, the noise cancels out a bit," says team member Riccardo Poli.

The technique can also compensate for a lapse in attention. "It is difficult to stay focused on the task at all times. So when a single user has momentary attention lapses, it matters. But when there are two users, a lapse by one will not have much effect, so you stay on target," Poli says.

NASA's Jet Propulsion Lab in Pasadena, California, has been observing the work while itself investigating BCI's potential for controlling planetary rovers, for example. But don't hold your breath, says JPL senior research scientist Adrian Stoica. "While potential uses for space applications exist, in terms of uses for planetary rover remote control, this is still a speculative idea," he says.

This article appeared in print under the headline "Two brains, one mind"

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A*STAR scientists solve century-old mystery in yeast infections

SINGAPORE: Scientists from the Agency for Science Technology And Research (A*STAR) have solved a century-old mystery in yeast infections.

They constructed stable strains of Candida albicans, the most prevalent human fungal pathogen and a major cause of hospital acquired infection.

A*STAR said on Friday that their discovery will help pave the way to develop drugs that effectively target and treat such infections.

Currently, the choice of drugs for this pathogen is limited.

Drugs resistance has also emerged worldwide, posing a great challenge to medicine.

The A*STAR scientists have shown that Candida albicans, long thought of as always having two copies of each chromosome and no sexual reproduction in its life, can and does exist as a sexually reproducing cell carrying only one copy of its genome.

The discovery fills a long missing gap in the life cycle of the pathogen and greatly advances the understanding of how it generates genetic variations.

The tools developed will help speed up the analyses of gene function and might speed up efforts to cure Candida infections.

- CNA/fa

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At least 25 killed in Mexico office blast, dozens injured

STORY HIGHLIGHTS

• NEW: 25 people were killed and more than 100 are injured, interior minister says


• The explosion collapsed two floors of an office building, paramedics say


• Rescuers have pulled a survivor from the rubble, Mexico's president says


• Crews are searching for people trapped in the building

Lea este artículo en español/Read this article in Spanish

Mexico City (CNN) -- An explosion rocked the offices of Mexico's state oil company Thursday, killing at least 25 people and injuring 101, Mexico's interior minister said.

Dozens of people were trapped in the building after the explosion, Foro TV reported. It was unclear how many of them had been pulled to safety, or whether anyone remained stuck inside late Thursday, Interior Minister Miguel Angel Osorio Chong told reporters.

More than five hours after the blast, rescuers had pulled at least one survivor from the rubble, Mexico's president said in a Twitter post.

Crews were still searching Thursday night for people who could be trapped in the Pemex office complex, which includes one of the city's tallest skyscrapers.

Explosion hits Mexican state oil company Pemex

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The explosion occurred in a basement and collapsed two floors of a building adjacent to the well-known tower, said Carlos Javier Rodriguez Jurado, one of the first paramedics to arrive at the scene.

The explosion tore through the building "from the inside out," he said, and rescuers found many people trapped. Six hours after the explosion, Rodriguez said people were likely still stuck in the rubble.

It was unclear what caused the blast, and Mexico's attorney general's office is investigating, Pemex said in a statement.

A large plume of smoke rose near the building after the explosion around 4 p.m. Thursday, and emergency crews swarmed the scene.

"People were screaming. ... You could see pieces of the wall falling to the ground," said Joaquin Borrell Valenzuela, an attorney for the Pemex comptroller's office, who was in a courtyard outside the building at the time of the blast.

Paramedics quickly arrived and started pulling bodies from the rubble.

"Entering the building, we smelled a strong odor of gas," said Christopher Rangel, a paramedic and firefighter.

Outside the building, frantic family members searched for loved ones, and shaken witnesses described the explosion.

Mario Guzman said he was on the 10th floor of the tower when he felt "a very strong blow."

"We felt like the whole building was going to collapse," he told CNNMexico.

Images from the scene showed emergency rescue teams carrying people on stretchers. Authorities said helicopters carried some of the wounded to hospitals.

At least 14 people were hospitalized with injuries, and two of them were in serious condition, the state-run Notimex news agency reported.

Mexican President Enrique Pena Nieto surveyed the damage Thursday night, along with Osorio Chong and Mexico City's mayor.

Pena Nieto cautioned against speculating over what caused the blast, and said authorities would be closely investigating.

Thousands of people work at the Pemex headquarters, which includes a 54-story building that is nearly 700 feet tall.

The explosion occurred in an annex building just to the east of the tower, Foreign Minister Jose Antonio Meade said.

Officials evacuated the complex and operations will cease there until further notice, the company said.

The state oil company's director, who was on a business trip in South Korea this week, said in a Twitter post that he would return to Mexico immediately.

"We will get to the bottom of the causes in close coordination with the authorities," Pemex Director General Emilio Lozoya Austin said. "At this time, attending to the injured is the priority."

Federal troops and rescue dogs were aiding in search efforts late Thursday night.

As they combed through the rubble, a Pemex executive's cell phone rang, Rangel said.

A man on the other end of the line said he was still trapped, and started to describe his location to rescuers.

"Unfortunately, we lost communication with him," Rangel said.

When they called back, his phone didn't ring.

CNN en Español's Krupskaia Alis reported from Mexico City. CNN's Catherine E. Shoichet reported from Atlanta. CNN's Rafael Romo, Edwin Mesa, Christine Theodorou, Rey Rodriguez, Rene Hernandez and CNNMexico's Arturo Ascencion and Javier Rodriguez contributed to this report.

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Alaska Airlines plane lands safely after pilot passes out

Updated 3 a.m. EST

PORTLAND, Ore. An Alaska Airlines jetliner bound for Seattle made an emergency landing in Portland, Ore., Thursday night after the pilot lost consciousness, an airline spokesman said.

The co-pilot landed Flight 473 safely after declaring an emergency to get priority care for the pilot, spokesman Paul McElroy said. All of the airlines' pilots are trained to fly single-handedly.

The pilot lost consciousness "somewhere over Oregon," McElroy said, then later regained consciousness and left the cockpit. A doctor on board the flight tended to him in the cabin until the plane landed and was met by medical personnel on the runway.

The pilot, who was not identified, was taken to a hospital but there was no immediate word on his condition, McElroy said.

The Boeing 737-700, with 116 passengers and five crew members on board, left Los Angeles about 6:30 p.m. and was diverted to Portland, touching down there at about 9 p.m., reports CBS Portland affiliate KOIN-TV. It had been due to arrive in Seattle at 9:30 p.m.

McElroy says the pilot has been flying for Alaska for 28 years and was current on his six-month medical evaluation. The co-pilot is an 11-year Alaska Air veteran.

On Jan. 22, the co-pilot on an Alaska Airlines flight from Seattle to Las Vegas fainted briefly, and the pilot requested emergency landing priority to get prompt medical assistance for him.

"At this point, we do not believe there was a connection between the two incidents," McElvoy said.

Twenty passengers with a tight schedule for connecting flights were put on a Horizon Air shuttle flight to Seattle on Thursday night, the spokesman said.

A new pilot was dispatched to Portland to fly the remaining passengers to Seattle on board the same plane.

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Keep rainforests – they drive the planet's winds

WHAT creates the wind? Anyone will tell you that temperature differences are key. Hot air rises and is replaced by cooler air surging in beneath. Except that maybe the explanation found in every textbook is too simple.

What if, instead, the winds that drive atmospheric circulation are mainly created by the condensation of moisture? Much of this occurs over rainforests as water evaporates or is transpired from the trees. The physicists and foresters behind this controversial idea say that if we chop down the forests, we will lose the winds - and the rains they bring with them.

The physical process itself is not in dispute. Whenever water vapour condenses to form droplets, its volume is reduced, lowering the pressure. Air moves in, creating wind.

Climate scientists have always regarded this as a trivial effect. Criticism has been heaped on the theory since it was first aired four years ago. "This is not a mysterious effect. It is small and included in some atmospheric models," says Isaac Held of the US National Oceanic and Atmospheric Administration in Princeton, New Jersey.

But physicist Anastassia Makarieva of St Petersburg University in Russia says the pressure gradients it would create "have never received a theoretical investigation". Her calculations suggest that the condensation of billions of litres of water above giant forests produces a giant effect (Atmospheric Chemistry and Physics, doi.org/kbx).

Co-author Douglas Sheil at Southern Cross University in Lismore, Australia, says critics have yet to explain why they think Makarieva is wrong. Until they do, he said, "this looks like a powerful mechanism that governs weather patterns round the world".

Judith Curry of the Georgia Institute of Technology, an author of the standard textbook Thermodynamics of Atmospheres and Oceans, is encouraging. "The process they describe is physically correct," she said. "The main question is its relative magnitude compared with other processes." She thinks it could explain why climate models do not get monsoons and hurricanes right.

Nobody doubts that forests recycle rain through evaporation and transpiration. But this is the first suggestion that this recycling process also whips up the winds that suck moist ocean air across continents.

The implications are huge. "In standard theories, if we lose forests the rainfall in the continental interiors generally declines by 10 to 30 per cent. In our theory, it is likely to decline by 90 per cent or more," says Sheil.

But it is not all bad news. If lost forests are replanted, the theory suggests, then the winds they generate could return rain to even the most arid lands. After all, the Sahara was lush swampland 6000 years ago.

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.

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